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Title: Charge-transfer processes in F{sup 2+}+H{yields}F{sup +}+H{sup +} collisions and the reverse process at low-keV energies

Abstract

Theoretical investigations on single charge-transfer processes in collisions of F{sup 2+}+H{yields}F{sup +}+H{sup +} and its reverse process have been carried out at collision energies from 20 eV/u to 10 keV/u. The molecular orbital expansion method within the semiclassical impact parameter formalism has been employed for the scattering dynamics, while the ab initio multireference single- and double-excitation configuration interaction (MRD-CI) method was adopted for determination of molecular electronic states. The initial channels correspond to the quintet and triplet states for the corresponding collision processes, respectively. Four molecular states in the quintet manifold and eight molecular states in the triplet manifold were coupled. In the quintet manifold, the charge-transfer cross sections for F{sup 2+}+H{yields}F{sup +}+H{sup +} range from 1.3x10{sup -22} cm{sup 2} at 20 eV/u to 2.5x10{sup -15}cm{sup 2} at 10 keV/u. The cross sections of the reverse process, F{sup +}+H{sup +}{yields}F{sup 2+}+H, range from 3.0x10{sup -22} cm{sup 2}to 2.3x10{sup -15} cm{sup 2} in the same energy range. In the triplet states, the charge-transfer cross sections for F{sup 2+}+H{yields}F{sup +}+H{sup +} range from 1.1x10{sup -18} cm{sup 2} to 2.5x10{sup -16} cm{sup 2}, and its reverse process gives charge-transfer cross sections ranging from 1.7x10{sup -24} cm{sup 2} to 1.5x10{sup -17} cm{sup 2}.

Authors:
;  [1]; ; ;  [2];  [3]
  1. Department of Physics and Astronomy, Rice University, M.S. 61, Houston, Texas 77251-1892 (United States)
  2. Fachbereich C-Mathematik and Naturwissenshaften, Bergische Universitaet Wuppertal, D-42097 Wuppertal (Germany)
  3. Graduate School of Sciences, Kyushu University, Hakozaki Fukuoka 812-8581 (Japan)
Publication Date:
OSTI Identifier:
20786518
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 72; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevA.72.052715; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ATOMS; CHARGE EXCHANGE; CONFIGURATION INTERACTION; CROSS SECTIONS; EV RANGE; EXCITATION; FLUORINE; FLUORINE IONS; HYDROGEN; HYDROGEN IONS 1 PLUS; IMPACT PARAMETER; ION-ATOM COLLISIONS; KEV RANGE; MOLECULAR ORBITAL METHOD; SCATTERING; SEMICLASSICAL APPROXIMATION; TRIPLETS

Citation Formats

Dutta, C. M., Nordlander, P., Gu, J. P., Hirsch, G., Buenker, R. J., and Kimura, M. Charge-transfer processes in F{sup 2+}+H{yields}F{sup +}+H{sup +} collisions and the reverse process at low-keV energies. United States: N. p., 2005. Web. doi:10.1103/PHYSREVA.72.0.
Dutta, C. M., Nordlander, P., Gu, J. P., Hirsch, G., Buenker, R. J., & Kimura, M. Charge-transfer processes in F{sup 2+}+H{yields}F{sup +}+H{sup +} collisions and the reverse process at low-keV energies. United States. doi:10.1103/PHYSREVA.72.0.
Dutta, C. M., Nordlander, P., Gu, J. P., Hirsch, G., Buenker, R. J., and Kimura, M. Tue . "Charge-transfer processes in F{sup 2+}+H{yields}F{sup +}+H{sup +} collisions and the reverse process at low-keV energies". United States. doi:10.1103/PHYSREVA.72.0.
@article{osti_20786518,
title = {Charge-transfer processes in F{sup 2+}+H{yields}F{sup +}+H{sup +} collisions and the reverse process at low-keV energies},
author = {Dutta, C. M. and Nordlander, P. and Gu, J. P. and Hirsch, G. and Buenker, R. J. and Kimura, M.},
abstractNote = {Theoretical investigations on single charge-transfer processes in collisions of F{sup 2+}+H{yields}F{sup +}+H{sup +} and its reverse process have been carried out at collision energies from 20 eV/u to 10 keV/u. The molecular orbital expansion method within the semiclassical impact parameter formalism has been employed for the scattering dynamics, while the ab initio multireference single- and double-excitation configuration interaction (MRD-CI) method was adopted for determination of molecular electronic states. The initial channels correspond to the quintet and triplet states for the corresponding collision processes, respectively. Four molecular states in the quintet manifold and eight molecular states in the triplet manifold were coupled. In the quintet manifold, the charge-transfer cross sections for F{sup 2+}+H{yields}F{sup +}+H{sup +} range from 1.3x10{sup -22} cm{sup 2} at 20 eV/u to 2.5x10{sup -15}cm{sup 2} at 10 keV/u. The cross sections of the reverse process, F{sup +}+H{sup +}{yields}F{sup 2+}+H, range from 3.0x10{sup -22} cm{sup 2}to 2.3x10{sup -15} cm{sup 2} in the same energy range. In the triplet states, the charge-transfer cross sections for F{sup 2+}+H{yields}F{sup +}+H{sup +} range from 1.1x10{sup -18} cm{sup 2} to 2.5x10{sup -16} cm{sup 2}, and its reverse process gives charge-transfer cross sections ranging from 1.7x10{sup -24} cm{sup 2} to 1.5x10{sup -17} cm{sup 2}.},
doi = {10.1103/PHYSREVA.72.0},
journal = {Physical Review. A},
number = 5,
volume = 72,
place = {United States},
year = {Tue Nov 15 00:00:00 EST 2005},
month = {Tue Nov 15 00:00:00 EST 2005}
}
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  • A theory for ion-atom collisions at low energies based on the hyperspherical close-coupling (HSCC) method is presented. In hyperspherical coordinates the wave function is expanded in analogy to the Born-Oppenheimer approximation where the adiabatic channel functions are calculated with B-spline basis functions while the coupled hyperradial equations are solved by a combination of R-matrix propagation and the slow/smooth variable discretization method. The HSCC method is applied to calculate charge-transfer cross sections for He{sup 2+}+H(1s){yields}He{sup +}(n=2)+H{sup +} reactions at center-of-mass energies from 10 eV to 4 keV. The results are shown to be in general good agreement with calculations based onmore » the molecular orbital (MO) expansion method where electron translation factors (ETF's) or switching functions have been incorporated in each MO. However, discrepancies were found at very low energies. It is shown that the HSCC method can be used to study low-energy ion-atom collisions without the need to introduce the ad hoc ETF's, and the results are free from ambiguities associated with the traditional MO expansion approach.« less
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